(This started out as a comment, but it got rather long, and I wanted to add more)
The embassy/consulate who issues visa are free to issue them with whatever validity period they like. If you haven't provided arguments for why you should get more than (e.g.) a week (I'm not sure Schengen visa can be that short) they might (and have the right to do so) think that one year is excessive.
Even though you and the company you work for might think it would be nice to get a visa with a long period of validity, you don't decide. The only thing you can do is build a history of not violating the terms of your visas (or the laws of the countries you visit).
Whatever you write is probably taken as an indication that they should look closely before issuing a visa with shorter validity as it might conflict with your plans. If you have reasonable plans but they misread a date, they might end up thinking a 30 day visa is sufficient, but if you've written that 32 days are needed, they might look over your plans again and discover their error.
It's typical to see that people who apply several times, gradually get visas with longer validity, but if they have you on record for applying for visas with longer validity than needed, that might make them less likely to do that.
It all also depends on where you come from.